Ping System for User Activated Audio Beacons Installed at the New York Hall
   of Science 

Touch Graphics has developed a new approach to improve accessibility to
public exhibit spaces such as science and technology museums. This concept
calls for creating a network of wireless audio beacons at key destinations in
the exhibit space that make it possible for blind and visually impaired
people to independently navigate and to learn about exhibit content. 

Links:
User-Activated Audio Beacons (Ping!)
http://www.touchgraphics.com/ping!.htm

Creating Accessible Science Museums with User-Activated Environmental Audio
   Beacons (Ping!) 
From: Assistive Technology 2005;17:133-143
http://www.touchgraphics.com/publications/resna-paper.pdf